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Unix Timestamp Converter
Convert Unix timestamps to UTC and local dates, or convert date strings to seconds and milliseconds locally in your browser.
Runs locally in your browser
Unix Timestamp Converter
Convert Unix seconds or milliseconds to readable dates, and convert date strings back to timestamps.
How to use it
What this Unix Timestamp Converter is for
Use this Unix Timestamp Converter when you need to debug API responses, log lines, database records, scheduled jobs, JWT claims, or JavaScript date values.
The tool runs locally in your browser. It does not upload timestamps, date strings, logs, or copied output to a server.
How to use it
Paste a Unix timestamp and choose Convert timestamp. The tool shows UTC time, local browser time, Unix seconds, Unix milliseconds, and ISO format.
You can also paste an ISO date such as:
2026-06-20T15:30:00ZThen choose Convert date to get the matching Unix seconds and milliseconds.
Seconds vs milliseconds
Backend APIs commonly use seconds. JavaScript Date.now() returns milliseconds.
If a value looks about 10 digits long, it is usually seconds. If it looks about 13 digits long, it is usually milliseconds. When in doubt, choose the unit manually instead of relying on auto-detection.
Related reading
Use the Cron Parser when debugging schedules, and use the JWT Decoder when inspecting timestamp claims such as iat, nbf, and exp. For API behavior context, read REST API Status Codes Explained and Idempotency in APIs Explained.
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Unix Timestamp Converter questions
Does this Unix Timestamp Converter upload my input?
No. Timestamp and date conversion runs locally in your browser, and the tool does not send input to a server.
What is a Unix timestamp?
A Unix timestamp is the number of seconds since 1970-01-01T00:00:00Z. Many JavaScript systems also use milliseconds since the same epoch.
Does this tool use seconds or milliseconds?
It can auto-detect common timestamp lengths, and you can also force seconds or milliseconds with the unit selector.
Why do UTC and local time look different?
UTC is a timezone-independent reference. Local time is displayed using your browser's current timezone settings.